Hardened core of bilayer shear bands in a Zr-based metallic glass

Bilayer shear bands with a spacing of hundreds of nanometers were prepared in a Zr-based metallic glass. Elastic properties of the bands were detected using a contact-resonance atomic force microscope. Compare with an elastic modulus reduction in each single shear band, the core of the bilayer shear bands is hardened. One possible reason for the forming of the bilayer shear bands is the load releasing and position adjustment during the severe plastic deformation process. Our results reveal a new plastic deformation mechanism of the shear bands in the form of layer by layer, and provide a promising strategy to control the stability of shear bands and enhance the plasticity of metallic glasses.